The invention belongs to the technical field of
lithium ion batteries, in particular relates to a composite
anode material for the
lithium ion battery. The composite
anode material comprises an
anode active substance and a
coating layer coated on the surface of the anode active substance, wherein the anode active substance can be Si, SiOx or
silicon alloy, the
coating layer is
polymer which is of a reticular structure, and the
mass percent of the
coating layer accounts for 1-20% of the anode material. Compared with the prior art, the composite anode material has the advantages that the
polymer which is of the reticular structure and used as the coating layer is coated on the surface of the active substance in a cross-linking manner, the coating layer has the
electron conduction property and the
ion conduction property, so that the situation that the
lithium ions can be inserted into and separated from the anode active substance particles smoothly is ensured; furthermore, the coating layer is of the reticular structure and has good
mechanical strength, and therefore, the integrality of the anode active substance particles can be kept in the electrochemical cycle process, the deformation of an anode strip is relieved, the electrochemical cycle performance of the
lithium ion battery is improved and the service life of the
lithium ion battery is prolonged.